I had the same problem and found out what it was:
lol, you MUST close the files you're working with.I inadvertently had "index.html" open and didn't notice it. The install couldn't work because one of the files it was trying to install was in use and therefore locked by windows. That's why the problem for most people seemed to eventually "Work with not problem, have no idea what the problem was": after closing the file in use, it magically started working.
Hope this helps for some.